ZFIN ID: ZDB-PUB-180628-2
Bsx controls pineal complex development
Schredelseker, T., Driever, W.
Date: 2018
Source: Development (Cambridge, England)   145(13): (Journal)
Registered Authors: Driever, Wolfgang, Schredelseker, Theresa
Keywords: Brain asymmetry, Brain-specific homeobox transcription factor, Bsx, Epithalamus, Habenula, Melatonin, Parapineal organ, Photoreceptors, Pineal gland
MeSH Terms:
  • Animals
  • Cell Differentiation/physiology*
  • Gene Expression Regulation, Developmental/physiology*
  • Homeodomain Proteins/biosynthesis*
  • Homeodomain Proteins/genetics
  • Melatonin/biosynthesis
  • Melatonin/genetics
  • Pineal Gland/cytology
  • Pineal Gland/embryology*
  • Zebrafish/embryology*
  • Zebrafish/genetics
  • Zebrafish Proteins/biosynthesis*
  • Zebrafish Proteins/genetics
PubMed: 29945867 Full text @ Development
Neuroendocrine cells in the pineal gland release melatonin during the night and, in teleosts, are directly photoreceptive. During development of the pineal complex, a small number of cells migrate leftward away from the pineal anlage to form the parapineal cell cluster, a process that is crucial for asymmetrical development of the bilateral habenular nuclei. Here, we show that, throughout zebrafish embryonic development, the brain-specific homeobox (bsx) gene is expressed in all cell types of the pineal complex. We identified Bmp and Noto/Flh as major regulators of bsx expression in the pineal complex. Upon loss of Bsx through the generation of a targeted mutation, embryos fail to form a parapineal organ and develop right-isomerized habenulae. Crucial enzymes in the melatonin biosynthesis pathway are not expressed, suggesting the absence of melatonin from the pineal gland in bsx mutants. Several genes involved in rod-like or cone-like phototransduction are also abnormally expressed, indicating that Bsx has a pivotal role in the differentiation of multiple cell types in the zebrafish pineal complex.